Failure Test And Failure Comparison Of SiC MOSFET And Si MOSFE

Power SiC MOSFETs have lower on-resistance,faster switching speeds,and greater high temperature capability.Due to its smaller chip area and thinner gate oxide layer,the reliability of SiC MOSFETs in short-circuit and avalanche conditions needs further investigation.Before any semiconductor device is put into use in large quantities,strict reliability research is necessary.Research on the reliability of power devices can obtain relevant data on device short-circuit capability and avalanche resistance.Analysis of short circuit and avalanche characteristics under different conditions can provide key information for designing protection circuits,application circuits and device optimization improvements.Due to the prominent advantages of SiC devices,in more and more occasions,Si-based devices are replaced by SiC devices.In this context,the reliability research of SiC MOSFET devices is particularly important.For power MOSFETs,short-circuit failure and avalanche Breakdown is two common types of failure.This article focuses on the short-circuit characteristics of SiC MOSFETs.Firstly,several common short-circuit types are introduced,and a short-circuit test experimental platform is designed.The LTspice simulation and experimental test of SiC MOSFET short circuit were carried out,and the influence of different parameters on the short circuit characteristics was studied.SiC MOSFET and Si MOSFET short-circuit failure experiments were performed to obtain the short-circuit tolerance of the device.Two types of failure modes of SiC MOSFET short-circuits were summarized.The electrothermal coupling model built in Saber was used to analyze the change of junction temperature during the short-circuit.Mechanism analysis.The results of this study can provide key parameters needed for the design of SiC MOSFET drive protection circuits.Through different avalanche tests of power SiC MOSFETs and Si MOSFETs with similar rated parameters of Cree and IXYS companies,the differences in avalanche characteristics are compared and analyzed under the same experimental conditions;the avalanche performance of power MOSFETs under different parameters is investigated.The avalanche failure mechanism is analyzed to provide a certain reference for the conditional design of power SiC MOSFETs in practical applications.